title: Effects of expiratory positive airway pressure on the electromyographic activity of accessory inspiratory muscles in COPD patients.
abstract: OBJECTIVE
  To evaluate the electromyographic activity (EA) of sternocleidomastoid (SCM) and scalene muscles during and after the use of expiratory positive airway pressure (EPAP) in patients with COPD.
  
  
  METHODS
  This was a clinical single-blind trial involving 13 healthy subjects as controls and 12 patients with stable COPD. At baseline, we determined EA during spontaneous respiration, lung function parameters, and respiratory muscle strength. Subsequently, EPAP at 15 cmH2O was applied by means of a face mask for 25 min, during which the EA of the SCM and scalene muscles was recorded every 5 min. A final record was obtained 10 min after the mask removal.
  
  
  RESULTS
  We found that the behavior of the EA of SCM and scalene muscles was comparable between the controls and the COPD patients (p = 0.716 and p = 0.789, respectively). However, during the use of EPAP, both muscles showed a trend toward an increase in the EA. In addition, there was a significant decrease in the EA of the SCM between the baseline and final measurements (p = 0.034).
  
  
  CONCLUSIONS
  The use of EPAP promoted a significant reduction in the EA of the SCM in the controls and in the patients with stable COPD. However, this did not occur regarding the EA of the scalene muscle.
authors.affiliation: Universidade Federal do Rio Grande do Sul-UFRGS, Federal University of Rio Grande do Sul-Porto Alegre, Brazil. dannuey@yahoo.com.br
authors.forename: Dannuey Machado
authors.initials: DM
authors.lastname: Cardoso
authors.forename: Dulciane Nunes
authors.initials: DN
authors.lastname: Paiva
authors.forename: Isabella Martins de
authors.initials: IM
authors.lastname: Albuquerque
authors.forename: Renan Trevisan
authors.initials: RT
authors.lastname: Jost
authors.forename: Andréia Vanessa da
authors.initials: AV
authors.lastname: Paixão
mesh_terms: D000328:Adult; D000368:Aged; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009334:Neck Muscles / Q000503:physiopathology*; D011175:Positive-Pressure Respiration; D029424:Pulmonary Disease, Chronic Obstructive / Q000503:physiopathology*; D012129:Respiratory Function Tests; D012132:Respiratory Muscles / Q000503:physiopathology*; D016037:Single-Blind Method